This invention relates to drain cleaners. Typical drain cleaners known to exist on the market are either liquid or granular.
Generally, the granular products contain sodium hydroxide, sodium nitrate, and aluminum. Sodium hydroxide is usually the largest component in these mixtures. The sodium hydroxide generates heat as it dissolves in water and reacts with the aluminum, thereby melting grease, soap, etc. which clog drains. Saponification of fats occurs due to the generated heat, changing the grease into a soap-like substance, which is more easily rinsed down the drain. Ammonia gas is generated to provide agitation and expose the clog to fresh sodium hydroxide. Most granular drain cleaners do not effectively remove hair clogs, as they contain no oxidizing agents. Generally dry oxidizers and hydroxides are not stable together.
The common liquid drain cleaners dissolve hair. They contain sodium or lithium hydroxide and sodium or lithium hypochlorite. The hydroxides are virtually ineffective against grease or soap build up because they are already in liquid form and therefore have no, or very little, heat of solution. Most liquid drain cleaners flow to the bottom of the trap or to the top of the clog due to their high density. This reduces the dilution caused by standing water and places more concentrated cleaner in contact with the clog.
Taylor et al., U.S. Pat. No. 4,664,836, teaches the use of a free-flowing crystalline drain cleaner composed of at least 40% coated alkali metal hydroxide and 5-20% hypochlorite generator and peroxide generator. The alkali metal hydroxide is coated to prevent the alkali metal hydroxide from reacting with the other components of the mixture. The peroxide generator produces peroxide which reacts to make the primary effervescent, dioxygen.
Steer et al., U.S. Pat. No. 5,630,883, teaches the method of removing a restriction from a drain system with the use of a non-caustic opening active in the drain cleaner. The non-caustic drain cleaner operates while maintaining a flow-through state in the pipe system.